JP5377487B2 - Method and apparatus for identifying thin films on a substrate - Google Patents

Description

Related applications

  This application is filed on Aug. 1, 2007 under the name “METHODS AND APPARATUS FOR IDENTIFYING THIN FILMS ON A SUBSTRATE”. No. 953,212 is claimed and this application is incorporated herein by reference for all purposes.

Field of Invention

  The present invention relates to the manufacture of electronic devices, and more particularly to a method and apparatus for identifying a thin film on a substrate disposed in a chamber.

Background of the Invention

  In an electronic device manufacturing process, it is important to be able to detect a layer or film (eg, a copper layer) deposited or otherwise positioned on a substrate while processing the substrate in a processing tool. There are many cases. For example, some film materials are incompatible with some chambers or processes, and bringing a substrate into an incompatible chamber can damage the chamber. Conventional devices for detecting membranes have a number of drawbacks in terms of complexity, cost, time and ease of use. Typically, conventional equipment requires the substrate to be removed from the processing tool for analysis. Accordingly, it would be desirable to provide a membrane detection device that would provide a combination of functionality, utility, waveform rate, application, low cost, setup and operational simplicity that would allow detection of membranes within the processing tool. .

  In some embodiments of the invention, a method for detecting a membrane is provided. A method for detecting a film in an electronic device disposed in an electronic device processing tool connects an attachment member of the film detection apparatus to a viewport of the electronic device processing tool, and uses a light energy source disposed in the attachment member. Illuminate the electronic device in the electronic device processing tool, pass the wavelength indicating the presence of the film through the optical system coupled to the mounting member, receive the light energy reflected by the substrate, and receive it using the optical detector Detecting the presence or absence of the film based on the measured light energy.

  In another aspect of the invention, an apparatus for detecting a membrane is provided. The present invention includes a mounting member configured to couple the apparatus to a viewport of an electronic device processing tool, and a light energy source disposed within the mounting member and configured to illuminate the electronic device within the electronic device processing tool. And an optical system configured to pass a wavelength indicative of the presence of the film, and positioned to receive light energy reflected by the substrate and passing through the optical system configured to detect the presence or absence of the film. An optical detection device.

  In yet another aspect of the invention, a system for detecting a membrane is provided. A system for detecting a film in an electronic device includes an electronic device processing tool, an attachment member configured to be coupled to a viewport of the electronic device processing tool, and an electronic device processing tool disposed within the attachment member A light energy source configured to illuminate an electronic device within, an optical system coupled to the mounting member and configured to pass a wavelength indicative of the presence of the film, and configured to detect the presence or absence of the film And an optical detector positioned to receive light energy reflected from the substrate and passing through the optical system.

  Other features and aspects of the present invention will become more fully apparent from the following detailed description, the appended claims and the accompanying drawings.

1 is an exploded perspective view of an embodiment of a first device of the present invention. FIG. 2 is a side view of the embodiment of the apparatus of FIG. FIG. 3 is a cross-sectional view of the embodiment of the apparatus of FIG. 2 taken along line 3-3. FIG. 2 is a detailed exploded perspective view of a portion of the embodiment of the apparatus of FIG. FIG. 5 is a detailed view of the embodiment of the component of FIG. 1 is a front perspective view of an embodiment of a first device of the present invention. FIG. FIG. 2 is a bottom perspective view of an embodiment of the apparatus of the present invention. FIG. 2 is a detailed exploded perspective view of a portion of the embodiment of the apparatus of FIG. 1 is a perspective view of an embodiment of the system of the present invention. 1 is a partial bottom perspective view of an embodiment of the system of the present invention. FIG. FIG. 2 shows an embodiment of the device of the present invention during execution of the first method of the present invention. FIG. 3 shows an embodiment of the device of the present invention during execution of the second method of the present invention. FIG. 6 is a front perspective view of a second apparatus embodiment of the present invention.

Detailed description

  The present invention provides an apparatus (“film detection apparatus”) for detecting a film in or on an electronic device, including a number of useful configurations. The accompanying drawings depict the structure and operation of one or more embodiments of a membrane detector according to the present invention.

  In one or more embodiments, the membrane detector is a Centura ™ or Endura ™ product from Applied Materials, Inc., Santa Clara, California. (Trade name)) and an integrated mounting member configured to be easily connectable to a viewport of one or more electronic device processing tools (eg, transfer chamber, processing chamber, etc.). The mounting member is designed to prevent light (eg, optical spectral energy) used by the film detector from reflecting off the viewport window (if it is left, the light is reflected off the window to detect the film) May affect the process). In order to detect thin films positioned under several other layers on a substrate in a processing tool, the film detector may include one or more optical spectral energies from infrared (about 1500 nm) to deep ultraviolet (about 150 nm). A source (“light source”), one or more optical detectors configured to detect a wavelength emitted by the light source and / or secondary light emission from the substrate, one or more diffusers, and an identification to be detected One or more narrowband filters configured to be sensitive to the membrane. The filter wavelength may be different from the wavelength emitted by the light source because, in some cases, secondary or shifted emission is reflected by the film on the substrate. By selecting the appropriate filter, the need for special alignment is eliminated. In order to assist detection, the membrane detection apparatus of the present invention may also include a configuration in which the ambient light source is blocked to reduce the background signal. It may include additional devices that reduce the effects of pattern shapes on the substrate by changing the optical path. Such devices include, but are not limited to, lenses, windows, collimators and diffusers. Automatic (eg, via control software) and / or manual mechanisms may be installed to control the intensity of energy emitted from the light source and the gain of the optical detector during operation.

  The membrane detector also includes a number of configurations that improve safety and reliability. For example, in some embodiments, the membrane detection device is coupled to limit and / or prevent unintentional exposure of the operator to the light energy source and to avoid disconnection of power when opening the enclosure. Including an enclosure having a shield designed to provide In one or more embodiments, the apparatus includes a safety interlock switch that prevents unintentional exposure to light energy beyond the eye-safe wavelength range.

  A stable light source (such as a solid light source that emits a fixed wavelength) can be used alone or in combination as appropriate. Such a light source is selected for a long and stable service life (e.g., 500 to 1000 times the service life of a light source used in conventional film detectors). If the light source is designed to be turned on in a very short time, it will only need to be powered for the short time needed to make a measurement and make a decision (no need to repeatedly calibrate), saving considerable energy. Safety is enhanced by turning on the light source very quickly and using it for a short time. For example, when using ultraviolet or infrared sources, exposure to them for a specific period of time is dangerous and only for a very short time when other safety standards (eg, shielding, enclosure closure) are met. The light source is powered.

  In addition, in some embodiments, the film detection apparatus is used as a substrate detection sensor for determining whether a substrate has been placed in the processing equipment. The substrate detection sensor may include a separate light source / optical detector assembly.

  The present invention also provides a control system and / or software configured to interfere and control the film detection apparatus according to the present invention. The control system may include one or more logic circuits configured to perform and record the calibration of the film detector, determine the presence or absence of the substrate, and be coupled to other control systems in the manufacturing facility. .

  In some embodiments, the present invention utilizes commercially available (e.g., Applied Materials Centura (TM) and Endura (TM)) transport chamber lid viewing window port specific mounting means (simple Bolt-on system). This attachment means would be easily adaptable to other types and styles of equipment.

  The present invention is designed to normally block ambient light sources for process uniformity. This is inherent in the design, which does not require additional technical methods or solutions.

  The present invention is designed to limit or prevent an operator from unintentionally being exposed to a light energy source. Other configurations include built-in safety shut-off switches (if necessary) and engineering safety solutions (such as wiring designs designed to prevent opening of the enclosure without power disconnection). By using these alone or in combination, the safety of the operator and the installation worker is enhanced. Conventional equipment often required a complex or difficult to use safety shield to achieve the same goal.

  The present invention is designed as a compact monolithic (modular) bolt-on assembly, in contrast to the prior art, which is assembled in-situ from various parts and its components are scattered throughout the system.

  The present invention is designed to interface with commercially available systems such as Centura (TM) and Endura (TM) substrate processing systems (e.g., plug and play). However, the interface is designed to be very simple in nature to enhance flexibility and can be easily adapted to other platforms and systems. The present invention may also include more complex system interfaces (such as serial data transfer) if desired, but the presence and use of such interfaces is not necessary for operation.

  In contrast to spectrographs and spectroscopes that are more suitable for analytical tasks and complex analyses, the present invention is designed to be task limited. A spectrograph and a spectroscope can be used to help determine the detection range to which this device is adapted, but once set, it is completely unnecessary for installation or use of the present invention.

  The setup of the present invention during manufacture is simple and it is sufficient to have a reasonable skill set. This device is tuned to the desired wavelength band by using standard commercially available narrowband optical filters and selecting the light source. No special alignment is required and very little if necessary.

  Solid light sources and / or other fixed wavelength energy sources may be used alone or in combination as appropriate. These are selected for long and stable operation (500 to 1000 times the useful life of conventional light sources). These devices can be considered permanent because they do not show significant degradation in their normal service life. A preferred light source is also “instant on” which does not require long preparation times. This means that power is supplied only for the short time needed to make a measurement and make a decision. For this reason, the light source does not require repeated recalibration and has a longer useful life. Furthermore, the light source is about 0.05% of the cost of a conventional light source, does not make noise during operation, and uses less than 1% energy for operation.

  The instant-on light source used in the present invention has enhanced safety. When using an ultraviolet or infrared source, the light source is powered only for a short time and only when all safety interlock criteria are met.

  The in-situ calibration of the present invention activates the system so that the calibration substrate passes through a simple substrate motion sequence or profile (eg, a portion of the major surface of the substrate passes under the system). Is achieved by scanning the calibration substrate as it moves along (moving the substrate in a horizontal pattern). This is completely different from conventional sensors that use spectrographs and spectroscopes or other more complex means.

  The present invention only takes 1-2% of the time and effort compared to conventional tools, correspondingly lowering the skill level required for both the installation worker and the operator.

  The present invention can be thought of as a “processing deviation” detection device. Traditional tools are designed as comprehensive “analytical instruments”, and while these traditional tools are configured to perform similar functions, they are expensive to set up, install, use, and maintain. It turns out to be difficult and time consuming.

  No special windows, optical fibers, vacuum seals or other are required for installation and use. During installation or use, existing vacuum seals are not broken. This allows for very quick installation and inspection without changes to the substrate manufacturing process or chamber.

  The present invention, in some embodiments, includes one or more optical spectral energy sources, and depending on the need for detection reliability, the wavelengths of these light sources can range from infrared (˜1500 nm) to deep ultraviolet (˜150 nm). ).

  The inclusion of an optional integrated safety interlock switch prevents technicians and operators from unintentionally being exposed to light energy that is outside the wavelength range safe for the eye or that is simply uncomfortable to see for extended periods of time. May be. Any eye-safe viewport window may exist as needed.

  Any separate substrate detection optical emitter and detection device may be included. This function can also be performed in most cases by the main membrane sensor. The present invention may include automated or manual means as part of a semi-automated calibration sequence to control the intensity of the light energy source during operation. The present invention may include automated or manual means as part of a semi-automated calibration sequence to control the gain or sensitivity of the detector during operation.

  The present invention may include an optical sensor or a group of optical sensors capable of detecting the wavelength emitted from the light energy source and / or the secondary emission from the substrate to be detected.

  The present invention may include one or more optical filters that are sensitive to the type of semiconductor substrate film being detected. The wavelength of the filter may or may not be the same as that of the integrated light energy source, which may be secondary emitted or shifted, even if the light energy source itself is monochromatic. This is because luminescence or a combination thereof is detected. The optical filter fixture is designed so that it can be easily reconfigured as needed.

  The present invention may include an optical path that limits the sensor to a particular area or range. Such paths include lenses, windows, collimators, diffusers and other devices that enhance this function and help to counteract the effects of pattern shapes on the substrate being detected.

  The present invention may include means for interfacing between the optical sensor and the host device. The present invention may include a logic circuit capable of performing and recording assembly calibration both under manufacturing and inspection conditions. The present invention may include a logic circuit capable of making a determination on a substrate film to be detected based on calibration. The present invention may include a logic circuit capable of determining the presence or absence of the substrate in the field of view of the detection device, including the case where the substrate front surface opening is not formed. The present invention may include a logic circuit that includes means for performing a semi-automated calibration routine. The present invention may also include means that are manually calibrated as needed. The present invention may include a logic circuit including means for connecting to substrate processing equipment control logic in a plug and play manner. This means that it can be easily adapted to other systems and devices.

  The present invention may include mechanical structures and optical paths that can operate without restricting movement of the blades and support arms of the robot handling the substrate. The present invention can include mounting features that prevent the first and second surface reflections from the vacuum chamber window from adversely affecting the returned detected optical signal. The present invention may include any integrated reference target surface for self-calibration or a standardized target substrate that helps to perform this calibration.

  The mechanical array device houses and aligns the light energy source and directs its output to a convergence point or controlled field.

  The present invention in other embodiments may include configurations of the invention as described above, except that an optical spectral energy source of one or more wavelengths may be present as needed (polychromatic aggregate light source). In some embodiments, one or more optical filters are included that are sensitive to the type of semiconductor substrate film being detected. It should be noted that the wavelength of the filter may or may not be the same as the light energy source incorporated. This is because, in some cases, secondary emission or shifted emission or a combination thereof is detected. In some embodiments, the multiplicity of optical wavelengths in the energy source may be selective, as needed, simultaneously or in sequence.

  The present invention in another embodiment includes the invention of the above embodiment except that any magnetic field detection means and high frequency electric field detection means are used with the optical spectrum sensor. Where applicable, any magnetic field detection means and high-frequency electric field detection means take the form of a detection coil mounted in proximity to the substrate under investigation, and in some cases, existing chamber view windows and mounts. Replaced mechanically.

  The invention in another embodiment includes the invention as described above, except that it uses a coaxial light source provided by a beam splitter, a double track optical fiber, a mirror or similar means. A coaxial light source can be used instead of a converging light source. A coaxial light source may be used with a converging light source and measurements may be made by using them separately, simultaneously or in combination.

  With reference to FIG. 1, a specific embodiment of the present invention will now be described for purposes of illustration. The exploded perspective view depicts an example film detection apparatus 100 of the present invention. The example apparatus 100 includes a light energy supply base assembly 102 that is configured to support an upper diffuser 104 and be surrounded by an outer tube housing 106. The outer tube housing 106 is also coupled to a base plate 108 that supports the optical sensor assembly 110 and is surrounded by a shield housing 112.

  The apparatus 100 is configured to be easily attached to a processing tool at a viewport (not shown) of a processing tool (not shown) (eg, transfer chamber, processing chamber, etc.). Once attached, the device both illuminates and scans the substrate in the processing tool via the viewport. The lower portion of the light energy supply base assembly 102 is shaped to fit into a viewport frame (not shown) so that the bottom annular surface (FIG. 2) of the assembly 102 is transparent to the viewport (e.g., The outer flange edge 204 (FIG. 2) of the assembly 102 overhangs the frame of the viewport to facilitate installation (eg, via bolts). In some embodiments, the structural members (eg, housing, base plate, etc.) of the device 100 are formed from aluminum or other practical material.

  The upper diffuser 104 can be formed from opal glass that is translucent but not transparent to light energy. In some embodiments, a thin layer of opal glass (eg, about 0.05 to about 0.3 mm thick, preferably about 0.1 mm thick) is replaced with a thicker transparent glass piece (eg, thick The upper diffuser 104 is formed by fusing to about 6 mm. An upper diffuser 104 is placed horizontally and in series with the central light energy path. The central light energy path is upwardly from the processing tool viewport, through the center of the light energy supply base assembly 102, through the upper diffuser 104, through the opening in the base plate 108 (including one or more optical filters). To) into the optical sensor assembly 110.

  The outer tube housing 106 (along with the shield housing 112) blocks the light energy supply base assembly 102, prevents ambient light from entering the optical sensor assembly 110, and exposes light energy from the light energy supply base assembly 102. It is configured to protect the operator from. Although the outer tube housing 106 is depicted as a tube, other shapes may be employed.

  An optical sensor assembly 110 is placed on and supported on the base plate 108. The optical sensor assembly 110 is configured to generate a signal indicative of detection of an energy wavelength of a particular target range in response to receiving light energy including the target range from the processing tool. For example, in some embodiments, a model PM100-V detection assembly (commercially available from Verity Instruments, Inc., Carrollton, TX) is used as the optical sensor assembly 110. In such embodiments, sensor assembly 110 is embodied as a replaceable or upgradeable modular component that is separate from the rest of the circuitry of device 100. In other embodiments, the optical sensor assembly 110 is embodied as an integrated component of the controller of the apparatus 100, for example as described below with respect to FIG. In some embodiments, the base plate 108 also supports an optical bandpass filter 306 (FIG. 3) in or adjacent to the opening between the optical sensor assembly 110 and the upper diffuser 104. As noted above, additional and other types of filters may be used.

  The shield housing 112 covers the top of the device 100 and encloses the controller and other circuitry (not visible in FIG. 1) of the device 100 in addition to the optical sensor assembly 110. Similar to the outer tube housing 106, the shield housing 112 prevents ambient light from entering the optical sensor assembly 110 and protects the operator from exposure to light energy from the light energy supply base assembly 102. It is configured.

  FIG. 2 is a side view of the apparatus 100 depicting how the various components illustrated in FIG. 1 are combined. It should be noted that the fasteners are omitted in both FIGS. 1 and 2 for the sake of clarity. As described above, the lower annular surface 202 of the apparatus 100 is configured to be flush with the window surface of the processing tool viewport. As also mentioned above, the outer flange edge 204 of the assembly 102 is configured to overhang from the viewport frame to facilitate attachment. Outer flange edge 204 includes a hole for securely and removably attaching the assembly to a processing tool (eg, via a bolt).

  FIG. 3 is a cross-sectional view of the apparatus example 100. The cross section is taken along the line identified as 3-3 in FIG. It should be noted that the elements described above with respect to FIGS. 1 and 2 have the same reference numbers as in FIGS. In FIG. 3, the light energy supply base assembly 102 and additional components of the apparatus 100 are depicted. Specifically, the lower diffuser 302 is depicted as being disposed within the inner diffusion tube 304. In addition, an optical bandpass filter 306 is depicted disposed between the upper diffuser 104 and the optical sensor assembly 110. A controller 308 is also depicted on the control circuit 310, which is supported by the shield housing 112. Control circuit 310 is coupled to optical sensor assembly 310 via cable 312.

  Similar to the upper diffuser 104, the lower diffuser 302 can be formed from opal glass. In some embodiments, a thin layer of opal glass (eg, about 0.05 to about 0.3 mm thick, preferably about 0.1 mm thick) is replaced with a thicker transparent glass piece (eg, thick The lower diffuser 302 is formed by fusing to about 0.6 mm. In some embodiments, the lower diffuser 302 is positioned such that the opal glass layer is on the upper surface of the lower diffuser 302 and the diffuser 302 is effectively pushed further into the inner diffusion tube 304.

  Inner diffusion tube 304 can be formed from aluminum and includes an inner surface 305 coated with a randomly textured material to further scatter and randomize light energy through tube 304. In some embodiments, the inner surface 305 of the inner diffusion tube 304 is anodized to form a coarse oxide layer. The thickness of the anodized layer may be about 32 microinch RMS.

  Controller 308 and control circuit 310 may include any combination of hardware and software configured to perform the methods of the present invention using processor, logic circuit and / or apparatus 100. For example, the controller 308 includes program code configured to operate the light energy supply base assembly 102 to illuminate the substrate in the processing tool in response to receiving a signal indicating the presence of the substrate. In some embodiments, the controller 308 includes program code configured to detect the presence of a substrate in the processing tool by using the light energy supply base assembly 102. In some embodiments, the controller 308 receives a signal from the optical sensor assembly 110 indicating that light energy of a particular wavelength coming from the substrate has been detected, and based on that signal, a particular material is present on the substrate. Program code configured to send a signal indicating detection to a host system or processing tool controller. In some embodiments, the controller 308 has program code configured to calibrate the apparatus 100, control the intensity of the light energy source, and / or adjust the gain of the sensor in the optical sensor assembly 110. Including. Controller 308 and control circuit 310 may also include interface ports, memory, clocks, power supplies, and other components to support the operation of controller 308.

  FIG. 4 is an exploded perspective view of the light energy supply base assembly 102. Note that fasteners are omitted for clarity. The light energy supply base assembly 102 includes a base mounting member 402 that supports both the lower diffuser 302 and the light energy source array 404 and is coupled to a processing tool viewport, as described above. It is configured. The light energy source base 102 further includes an upper support member 408 configured to hold the inner diffusion tube 304 and the upper diffuser 104. Since the internal diffusion tube 304 is configured to extend from the base mounting member 402 to the upper support member 406, a path for flowing light energy reflected by the substrate to the optical sensor assembly 110 is defined. The outer tube housing 106 is disposed around the optical energy supply base assembly 102 by fitting a spacer 410 (eg, O-ring) into the groove of the upper support member 408, and the relative movement between the member 408 and the assembly 102 Can be prevented. The spacer 410 may also serve to secure and hold the cable between the light energy supply base assembly 102 and the control circuit 310.

  In addition to providing a means for easily and removably coupling device 100 to a processing tool viewport, base mounting member 402 supports both lower diffuser 302 and light energy source array 404. Including a number of openings for. In particular, the openings include a plurality of generally standard openings for LEDs and other energy sources and a pair of angled openings for the substrate detection emitter / sensor pair.

  FIG. 5 is a diagram of a light energy source array 404. The illustrated array 404 includes six LEDs 502. However, depending on the corresponding number of openings in the base mounting member 402, any number and type of practical light energy sources may be used. As described above, a variety of different types of energy sources can be used to generate optical spectral energy ranging from infrared (about 1500 nm) to deep ultraviolet (about 150 nm).

  In some embodiments as illustrated in FIG. 5, the light energy source array 404 further includes an emitter 504 and a sensor 506, which are used together to form a substrate detection emitter / sensor pair. In addition to the cable, the light energy source array 404 further includes a connector 508 configured to connect to the interface port of the control circuit 310, which makes the device easier to manufacture and repair.

  6 and 7 are a front perspective view and a bottom perspective view of the film detection apparatus 100, respectively. It should be noted that the apparatus 100 can be configured low relative to the lid of the processing tool that is to be attached. The length of the inner diffusion tube 304 is generally defined by the desired vertical dimension, and as the length increases, the amount of diffusion increases, thereby improving the signal to noise ratio of the device 100. With respect to FIG. 7, it should be noted that the relative positions of the LEDs 502 disposed around the lower diffuser 302 to create a uniform field of “view” cones that overlap on the substrate. It should also be noted that the flat annular surface 202 is configured to be flush with the processing tool viewport window.

  FIG. 8 is a detailed exploded perspective view of the lower portion of the light energy supply base assembly 102. In particular, FIG. 8 depicts the relative positions of the lower diffuser 302, internal diffusion tube 304, LED 502, emitter 504, and sensor 506, and how each fits into the base mounting member 402. Emitter 504 and sensor 506 are depicted at an angle of approximately 22.5 ° so that light energy from emitter 504 can be reflected by the substrate and received by sensor 506. Other practical angles may be employed.

  FIG. 9 is a perspective view of a system embodiment of the present invention. Two film detection apparatuses 100 are depicted in a state where they are connected to a part of a cover 902 of a processing tool such as a transfer chamber. The lid 902 includes a plurality of viewports 904, each viewport including a frame 906 and a transparent window material 908. The device 100 of the present invention is depicted bolted to a frame 906 of two viewports 904, with a flat annular surface 202 (FIG. 8) and a transparent window material 908 fitted within the frame 906. It becomes the same plane. In the illustrated configuration, ambient light cannot enter the device 100 except through the transparent window material 908.

  FIG. 10 is a perspective view of the second embodiment of the film detection apparatus 1000. It should be noted that this embodiment is similar to the embodiment of FIG. 1 except that the outer housing has a different shape and dimensions. The apparatus 1000 also includes an adjustment unit 1002 that can change the position of the upper diffuser. Device 1000 is depicted coupled to frame 906 of viewport 904 with a lid (omitted for clarity).

  Light energy rays 1004 are emitted from emitter 504, pass through transparent window material 908, reflect off substrate surface 1006, pass through transparent window material 908 again, and are received by sensor 506. As shown, when a substrate is present, the light energy rays 1004 are reflected by the substrate surface 1006 and the substrate is detected. When the substrate is not present, the light energy ray 1004 is reflected and does not return to the sensor 506, so that the apparatus 1000 can determine that the substrate is not present.

  FIG. 11 is a cross-sectional view depicting the trajectory of the light energy line represented as a perspective view in FIG. Similar to FIG. 10, light energy rays 1004 are emitted from emitter 504, pass through transparent window material 908, reflect off substrate surface 1006, pass through transparent window material 908 again, and are received by sensor 506. ing. As shown, when a substrate is present, the light energy rays 1004 are reflected by the substrate surface 1006 and the substrate is detected. When the substrate is not present, the light energy ray 1004 is reflected and does not return to the sensor 506, so that the apparatus 1000 can determine that the substrate is not present.

  It should be noted that some light energy rays 1102 are reflected by the transparent window material 908 toward the lower diffuser 302, although this is not a concern in the illustrated method of determining the presence of the substrate. For this reason, it is preferable to turn off the emitter 504 when the present invention is used to detect the presence of a film on a substrate.

  FIG. 12 is a locus diagram of optical energy lines depicting a part of the path of optical spectral energy. The trajectory of the light energy ray is shown using the cross-sectional view of the third embodiment of the film detector 1200. Different configurations of the example apparatus 1200 of FIG. 12 are described in more detail below in connection with FIG.

  The device 1200 causes light energy rays 1204 to be emitted from the LED 502. The light energy lines 1204 form a uniform, overlapping pattern of circular energy fields that are reflected off the substrate 1006 and return to the lower diffuser 302. The wavelength of the LED 502 is selected to generate an energy ray 1204 that reflects better with the material to be detected than with other materials. Therefore, more energy is reflected when the target detection material is present. During operation, the apparatus of the present invention detects the difference in the amount of optical spectral energy reflected by the substrate. Preferably, the wavelengths are selected so that the target detection material and other non-target detection materials have a difference of about 20% in intensity when reflected. Other percentage intensity differences may be employed to determine the presence of the target detection material.

  Since the electronic device on the substrate does not reflect energy uniformly due to its shape, imaging effects and other reasons in addition to the specific material present, the present invention reflects the energy reflected by the specific material present. Diffusion is used to mitigate the effects of shape, imaging effects and other reasons while maintaining the amount of. In other words, the use of diffusion reduces the influence of shape, imaging effects, and other reasons without affecting the relative amount of energy reflected by the film on the substrate. With embodiments of the present invention, accurate, reproducible and reliable film detection is achieved with a signal to noise ratio of less than about 2%, preferably less than about 1%.

  After the light energy rays 1204 are reflected off the substrate 1006, the light energy rays 1102 pass through the viewport transparent window material 908 toward the lower diffuser 302. It should be noted that the light energy rays 1102 reflected by the transparent window material 908 are blocked from reaching the lower diffuser 302 by the base mounting member 402. Indeed, the shape of the present invention is designed so that only the light energy rays 1204 reflected by the substrate 1006 reach the lower diffuser 302 and ultimately the sensor 1202.

  Embodiments of the present invention utilize three stages of diffusion. The light energy rays 1204 are first diffused through the lower diffuser 302, then further randomized by the inner surface 305 of the inner diffusion tube 304, and finally pass through the upper diffuser 104. In some embodiments, certain wavelengths are filtered by using an optical bandpass or other filter 306, as described above. The light energy line 1204 then reaches the sensor 1202 and the presence of the target detection material is indicated by the relative amount of energy detected at a predetermined wavelength associated with the target detection material.

  FIG. 13 is a more detailed cross-sectional view of the third embodiment of the film detector 1200. Elements corresponding to the above configuration are identified with the same reference numbers as used in the description of the above embodiments. The main difference between the membrane detector 1200 and the membrane detector 100 is the elimination of the separation optical sensor assembly 110 from the membrane detector 1200. Instead, sensor 1202 is integrated into control circuit 310. This difference further reduces the cost and complexity of the present invention.

  The embodiments described herein are merely possible examples of substrate film sensor configurations, and these variations are also considered to be within the basic concept of the present invention. That is, the above description discloses only exemplary embodiments of the invention. Modifications to the above-disclosed apparatus and method that fall within the scope of the invention will be apparent to those skilled in the art. Accordingly, while the invention has been disclosed in connection with specific exemplary embodiments thereof, other embodiments are within the spirit and scope of the invention as defined by the following claims. Should be understood.

Claims (7)

An apparatus for detecting a film on a substrate in an electronic device processing tool,
A mounting member configured to couple the apparatus to a viewport of the electronic device processing tool;
A light energy source disposed within the mounting member and configured to illuminate the substrate within the electronic device processing tool;
An additional light energy source,
An optical system configured to pass wavelengths indicative of the presence of the film;
An optical detection device positioned to receive light energy reflected by the substrate and passing through the optical system and configured to detect the presence or absence of the film ;
An additional optical detection device arranged to receive the light energy reflected by the substrate ,
The mounting member includes a base plate having one or more openings arranged to support the light energy source;
The optical system comprises a diffusion tube having a diffuser disposed at either end of the diffusion tube;
The diffusion tube defines a path for the light energy reflected from the substrate to flow to the optical detection device ,
An apparatus wherein the additional light energy source and the additional optical detection device are configured to detect the presence or absence of a substrate in the electronic device processing tool .   The apparatus of claim 1, further comprising a housing configured to prevent light energy that is coupled to the mounting member and not reflected by the substrate from reaching the optical detector.   The apparatus of claim 1, wherein the optical system includes a plurality of diffusers and a filter. A system for detecting a film on a substrate,
An electronic device processing tool;
A mounting member configured to be coupled to a viewport of the electronic device processing tool;
A light energy source disposed within the mounting member and configured to illuminate a substrate within the electronic device processing tool;
An additional light energy source,
An optical system coupled to the mounting member and configured to pass wavelengths indicative of the presence of the film;
An optical detection device positioned to receive light energy reflected by the substrate and passing through the optical system and configured to detect the presence or absence of the film ;
An additional optical detection device arranged to receive the light energy reflected by the substrate ,
The mounting member includes a base plate having one or more openings arranged to support the light energy source;
The optical system comprises a diffusion tube having a diffuser disposed at either end of the diffusion tube;
The diffusion tube defines a path for the light energy reflected from the substrate to flow to the optical detection device ,
A system in which an additional light energy source and an additional optical detection device are configured to detect the presence or absence of a substrate in an electronic device processing tool . 5. The system of claim 4 , further comprising a housing configured to prevent light energy that is coupled to the mounting member and not reflected by the substrate from reaching the optical detection device. The system of claim 4, wherein the optical system includes a plurality of diffusers and a filter. A method for detecting a film on a substrate disposed in an electronic device processing tool comprising:
Connecting the mounting member of the film detector to the viewport of the electronic device processing tool,
Illuminating a substrate in the electronic device processing tool using a light energy source and an additional light energy source disposed within the mounting member;
Let the optical system connected to the mounting member pass a wavelength indicating the presence of the film,
Receives the light energy reflected by the substrate,
Using optical detection apparatus and additional optical detection device includes that you detect the presence or absence of a film based on the light energy received,
The mounting member includes a base plate having one or more openings arranged to support the light energy source;
The optical system comprises a diffusion tube having a diffuser disposed at either end of the diffusion tube;
The diffusion tube defines a path for the light energy reflected from the substrate to flow to the optical detection device ,
The method wherein the additional light energy source and the additional optical detection apparatus are configured to detect the presence or absence of a substrate in the electronic device processing tool .

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